--- a/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.phases.common/src/org/graalvm/compiler/phases/common/CanonicalizerPhase.java	Tue Apr 24 08:13:30 2018 -0700
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.phases.common/src/org/graalvm/compiler/phases/common/CanonicalizerPhase.java	Tue Apr 24 09:04:57 2018 -0700
@@ -314,7 +314,7 @@
 
         @SuppressWarnings("try")
         public boolean tryCanonicalize(final Node node, NodeClass<?> nodeClass) {
-            try (DebugCloseable position = node.withNodeSourcePosition()) {
+            try (DebugCloseable position = node.withNodeSourcePosition(); DebugContext.Scope scope = debug.scope("tryCanonicalize", node)) {
                 if (customCanonicalizer != null) {
                     Node canonical = customCanonicalizer.canonicalize(node);
                     if (performReplacement(node, canonical)) {
@@ -349,6 +349,8 @@
                     return node.isDeleted();
                 }
                 return false;
+            } catch (Throwable throwable) {
+                throw debug.handle(throwable);
             }
         }